Programmatically remove users from app and dataset permissisons

Hi all,

I've been tasked with cleaning up a tenant where the prior developers assigned workspace app permissions to individual users instead of leveraging security group/distribution lists. I am in the process of replacing the users with groups. This is easy enough to repalce users with groups and republish the app. But the permissions granted on each dataset in the workspace remain. I can manually click through dataset direct permissons and remove the access but this is very time consuming since there were 100's sometime over 1000 users added indivudually and 10's of datasets per workspace (my wrist will not be happy).

I've searched and can not find a REST API method or Power Shell cmdlet to programatically delete an individuals user permissions from each data set. Am I missing something or is manually the only way to accomplish this?

Thanks!